To meet the demand for wireless data traffic having increased since deployment of 4th generation (4G) communication systems, efforts have been made to develop an improved 5th generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post LTE System’.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
In a Public Safety (PS) environment in which a disaster such as an earthquake, fire, and the like has occurred, some Base Stations (BSs) cannot function and thus particular User Equipments (UEs) cannot communicate. At this time, a relay scheme using a UE within the communication coverage of another BS that can function may be used.
The relay scheme is based on D2D communication. The UE that cannot communicate may transmit data to a relay UE that provides a relay service based on a D2D communication scheme. The relay UE having received the data may transmit a received message to the BS based on a cellular communication scheme.
In this case, when the number of remote UEs that transmit data through the relay UE increases, connections may be concentrated into a particular relay UE and thus a delay of the relay service may occur due to relay overload.